lambency vs radiancy

lambency and radiancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
lambency	Yes	No	No	No
radiancy	Yes	No	No	No

As nouns, radiancy is a hypernym of lambency; that is, radiancy is a word with a broader meaning than lambency:

Other hypernyms of lambency include effulgence, radiance, refulgence, refulgency, shine.

lambency (noun)	radiancy (noun)
an appearance of reflected light	the quality of being bright and sending out rays of light